Cleaning agent composition and cleaning method

ABSTRACT

A cleaning agent composition for use in removal of a polysiloxane adhesive remaining on a substrate, the composition containing a tetrahydrocarbylammonium fluoride and an organic solvent, wherein the organic solvent contains an aromatic compound represented by formula (1) and a lactam compound represented by formula (2).(in formulas (1) and (2), s represents the number of substituents R100s of the benzene ring and is 2 or 3; s groups of R100s each independently represent a C1 to C6 alkyl group; the total number of carbon atoms in s groups of C1 to C6 alkyl groups is 3 or greater; R101 represents a C1 to C6 alkyl group; and R102 represents a C1 to C6 alkylene group.)

TECHNICAL FIELD

The present invention relates to a cleaning agent composition for use inremoval of an adhesive residue remaining after, for example, debonding alaminate which has been temporarily bonded by the mediation of anadhesive layer formed from a polysiloxane adhesive and on asemiconductor substrate. The invention also relates to a cleaning methodmaking use of the adhesive agent composition.

BACKGROUND ART

Conventionally, electronic elements and wires are 2-dimensionally(within a plane) integrated on a semiconductor wafer. In a trend towardfurther integration, demand has arisen for a semiconductor integrationtechnique which achieves 3-dimensional integration (i.e., stacking) inaddition to 2-dimensional integration. In the technique of 3-dimensionalintegration, a number of layers are stacked by the mediation of throughsilicon vias (TSVs). In integration of multiple layers, each componentwafer to be stacked is thinned by polishing (i.e., grinding) a surfaceopposite the circuit-furnished surface (i.e., a back surface), and thethus-thinned semiconductor wafers are stacked.

Before thinning, the semiconductor wafer (may also be called simply“wafer”) is fixed to a support for facilitating polishing by means of apolishing machine (i.e., grinder). Since the fixation must be easilyremoved after polishing, the fixation is called temporary bonding.Temporary bonding must be easily removed from the support. When suchtemporary bonding is removed by excessive force, in some cases a thinnedsemiconductor wafer may be broken or deformed. In order to prevent sucha phenomenon, the temporarily bonded support is detached in a gentlemanner. However, from another aspect, it is not preferred that thetemporarily bonded support be removed or slid by a stress applied duringpolishing of the back surface of the semiconductor wafer. Therefore,temporary bonding must withstand the stress during polishing and must beeasily removed after polishing. For example, one required performanceincludes having high stress (i.e., strong adhesion) within the planeduring polishing and low stress (i.e., weak adhesion) toward thethickness direction during detaching. Furthermore, in processing steps,the temperature of a workpiece may exceed 150° C. in some cases. Thus,temporary bonding must be stable at such high temperatures.

Under such circumstances, polysiloxane adhesives meeting theaforementioned characteristic requirements are mainly used as temporaryadhesives in the semiconductor industry. In temporary bonding by use ofa polysiloxane adhesive, an adhesive residue often remains on asubstrate surface after removal of the thinned substrate. In order toavoid an undesired phenomenon in a subsequent step, there has beendeveloped a cleaning agent composition for removing such a residue andcleaning the surface of a semiconductor substrate (see, for example,Patent Documents 1 and 2). Currently, there is continuous demand for anew cleaning agent composition in the semiconductor field. PatentDocument 1 discloses a siloxane resin-remover containing a polar,aprotic solvent and a quaternary ammonium hydroxide, and Patent Document2 discloses a cured resin-remover containing an alkylammonium fluoride.However, development of a more effective cleaning agent composition isexpected.

PRIOR ART DOCUMENTS Patent Documents

-   Patent Document 1: WO 2014/092022-   Patent Document 2: U.S. Pat. No. 6,818,608

SUMMARY OF THE INVENTION Problems to be Solved by the Invention

The present invention has been conceived in view of the foregoing. Thus,an object of the invention is to provide a cleaning agent compositionwhich has excellent cleaning performance, in cleaning of a substrate(e.g., a semiconductor substrate), with respect to an adhesive residueremaining after debonding a laminate that has been temporarily bonded bythe mediation of an adhesive layer formed from a polysiloxane adhesiveand on a semiconductor substrate and which can clean the substrate athigh efficiency without corroding the substrate. Another object is toprovide a cleaning method using the composition.

Means for Solving the Problems

The present inventors have conducted extensive studies to attain theaforementioned objects, and have found the following. In cleaning of asubstrate (e.g., a semiconductor substrate) on which an adhesive residueremains after debonding a laminate that has been temporarily bonded bythe mediation of an adhesive layer formed from a polysiloxane adhesive,the substrate can be suitably cleaned at high efficiency in a simplemanner without corroding the substrate, by use of a cleaning agentcomposition containing a tetrahydrocarbylammonium fluoride and anorganic solvent, wherein the organic solvent contains an aromaticcompound represented by formula (1) and a lactam compound represented byformula (2). The present invention has been accomplished on the basis ofthis finding.

Notably, neither Patent Document 1 nor 2 teaches or suggests a specifictechnical feature of the cleaning agent composition of the presentinvention.

Accordingly, the present invention provides the following.

-   -   1. A cleaning agent composition for use in removal of a        polysiloxane adhesive remaining on a substrate, characterized in        that the composition comprises a tetrahydrocarbylammonium        fluoride and an organic solvent, wherein the organic solvent        contains an aromatic compound represented by formula (1) and a        lactam compound represented by formula (2):

(wherein s represents the number of substituents R¹⁰⁰s of the benzenering and is 2 or 3; s groups of R¹⁰⁰s each independently represent a C1to C6 alkyl group; the total number of carbon atoms in s groups of C1 toC6 alkyl groups is 3 or greater; R¹⁰¹ represents a C1 to C6 alkyl group;and R¹⁰² represents a C1 to C6 alkylene group).

-   -   2. A cleaning agent composition according to 1 above, wherein        the lactam compound includes at least one member selected from        N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone.    -   3. A cleaning agent composition according to 1 or 2 above,        wherein the aromatic compound includes at least one member        selected from among 1,2,3-trimethylbenzene,        1,2,4-trimethylbenzene, 1,2,5-trimethylbenzene,        1,3,5-trimethylbenzene, 4-ethyltoluene, 4-n-propyltoluene,        4-isopropyltoluene, 4-n-butyltoluene, 4-s-butyltoluene,        4-isobutyltoluene, and 4-t-butyltoluene.    -   4. A cleaning agent composition according to any of 1 to 3        above, wherein the tetrahydrocarbylammonium fluoride includes at        least one member selected from among tetramethylammonium        fluoride, tetraethylammonium fluoride, tetrapropylammonium        fluoride, and tetrabutylammonium fluoride.    -   5. A cleaning agent composition according to any of 1 to 4        above, wherein the ratio by mass of the aromatic compound to the        lactam compound (aromatic compound:lactam compound) is 30:70 to        80:20.    -   6. A cleaning agent composition according to 1 above, wherein        the lactam compound includes at least one member selected from        N-methyl-2-pyrrolidone and N-ethyl-2-pyrrolidone; the aromatic        compound includes at least one member selected from among        1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene,        1,2,5-trimethylbenzene, 1,3,5-trimethylbenzene, 4-ethyltoluene,        4-n-propyltoluene, 4-isopropyltoluene, 4-n-butyltoluene,        4-s-butyltoluene, 4-isobutyltoluene, and 4-t-butyltoluene; and        the tetrahydrocarbylammonium fluoride includes at least one        member selected from among tetramethylammonium fluoride,        tetraethylammonium fluoride, tetrapropylammonium fluoride, and        tetrabutylammonium fluoride.    -   7. A cleaning agent composition according to 6 above, wherein        the ratio of the aromatic compound to the lactam compound        (aromatic compound:lactam compound) is 30:70 to 80:20.    -   8. A cleaning agent composition according to any of 1 to 7        above, wherein the polysiloxane adhesive remaining on a        substrate is an adhesive residue originating from an adhesive        layer formed from an adhesive composition containing a        component (A) which is cured through hydrosilylation.    -   9. A cleaning method, characterized by comprising removing an        adhesive residue remaining on a substrate by use of a cleaning        agent composition as recited in any of 1 to 8 above.    -   10. A method for producing a processed semiconductor substrate,        the method comprising a first step of producing a laminate        including a semiconductor substrate, a support substrate, and an        adhesive layer formed from an adhesive composition; a second        step of processing the semiconductor substrate of the produced        laminate; a third step of debonding the semiconductor substrate        after processing; and a fourth step of removing an adhesive        residue remaining on the debonded semiconductor substrate with a        cleaning agent composition, characterized in that a cleaning        agent composition as recited in any of 1 to 8 above is used as        the cleaning agent composition.

Effects of the Invention

According to the cleaning agent composition of the present invention, asubstrate (e.g., a semiconductor substrate) on which an adhesive residueremains after debonding a laminate which has been temporarily bonded bythe mediation of an adhesive layer formed from a polysiloxane adhesivecan be cleaned at high efficiency in a short period of time withoutcorroding the substrate. The cleaning can be accomplished only through asimple operation; i.e., bringing a cleaning target surface into contactwith the cleaning agent composition.

MODES FOR CARRYING OUT THE INVENTION

The present invention will next be described in more detail.

The cleaning agent composition of the present invention is directed to acleaning agent composition for use in removal of a polysiloxane adhesiveremaining on a substrate, and the composition contains atetrahydrocarbylammonium fluoride and an organic solvent, wherein theorganic solvent contains an aromatic compound represented by formula (1)and a lactam compound represented by formula (2):

(wherein s represents the number of substituents R¹⁰⁰s of the benzenering and is 2 or 3; s groups of R¹⁰⁰s each independently represent a C1to C6 alkyl group; the total number of carbon atoms in s groups of C1 toC6 alkyl groups is 3 or greater; R¹⁰¹ represents a C1 to C6 alkyl group;and R¹⁰² represents a C1 to C6 alkylene group).

Specific examples of the hydrocarbyl group of thetetrahydrocarbylammonium fluoride include a C1 to C20 alkyl group, a C2to C20 alkenyl group, a C2 to C20 alkynyl group, and a C6 to C20 arylgroup.

In one preferred embodiment of the present invention, thetetrahydrocarbylammonium fluoride includes tetraalkylammonium fluoride.

Specific examples of the tetraalkylammonium fluoride include, but arenot limited to, tetramethylammonium fluoride, tetraethylammoniumfluoride, tetrapropylammonium fluoride, and tetrabutylammonium fluoride.Of these, tetrabutylammonium fluoride is preferred.

Notably, a tetrahydrocarbylammonium fluoride hydrate may be used. Also,these tetrahydrocarbylammonium fluorides may be used singly or incombination of two or more species.

No particular limitation is imposed on the amount of thetetrahydrocarbylammonium fluoride, so long as it can be dissolved in thesolvent contained in the cleaning agent composition. The amount isgenerally 0.1 to 30 mass % based on the amount of the cleaning agentcomposition.

Specific examples of the C1 to C6 alkyl group in formula (1) include,but are not limited to, methyl, ethyl, n-propyl, n-butyl, isobutyl,s-butyl, and t-butyl.

The “s” represents the number of substituents R¹⁰⁰s of the benzene ringand is 2 or 3.

In one preferred embodiment of the present invention, the aromaticcompound represented by formula (1) is an aromatic compound representedby formula (1-1-1) or (1-2):

(wherein R¹⁰⁰s each represent a C1 to C6 alkyl group; the total numberof carbon atoms in three C1 to C6 alkyl groups of R¹⁰⁰ in formula (1-1)is 3 or greater; and the total number of carbon atoms in two C1 to C6alkyl groups of R¹⁰⁰ in formula (1-2) is 3 or greater).

Specific examples of the aromatic compound represented by formula (1)include, but are not limited to, 1,2,3-trimethylbenzene,1,2,4-trimethylbenzene, 1,2,5-trimethylbenzene, 1,3,5-trimethylbenzene(mesitylene), 4-ethyltoluene, 4-n-propyltoluene, 4-isopropyltoluene,4-n-butyltoluene, 4-s-butyltoluene, 4-isobutyltoluene, and4-t-butyltoluene.

Of these, mesitylene and 4-t-butyltoluene are preferred.

The amount of the aromatic compound represented by formula (1) isgenerally 1 to 98.9 mass % based on the amount of the cleaning agentcomposition.

Specific examples of the C1 to C6 alkyl group in formula (2) include,but are not limited to, methyl, ethyl, n-propyl, n-butyl, isobutyl,s-butyl, and t-butyl. Specific examples of the C1 to C6 alkylene groupin formula (2) include, but are not limited to, methylene, ethylene,trimethylene, tetramethylene, pentamethylene, and hexamethylene.

Specific examples of the lactam compound represented by formula (2)include an α-lactam compound, a β-lactam compound, a γ-lactam compound,and a δ-lactam compound. These lactam compounds may be used singly or incombination of two or more species.

In one preferred embodiment of the present invention, the lactamcompound represented by formula (2) includes a 1-alkyl-2-pyrrolidone(N-alkyl-γ-butyrolactam). In a more preferred embodiment, the lactamcompound includes N-methylpyrrolidone (NMP) or N-ethylpyrrolidone (NEP).In a still more preferred embodiment, the lactam compound includesN-methylpyrrolidone (NMP).

The amount of the lactam compound represented by formula (2) isgenerally 1 to 98.9 mass % based on the amount of the cleaning agentcomposition.

The ratio (by mass) of the aromatic compound represented by formula (1)to the lactam compound represented by formula (2) may be tuned to anyvalue. Preferably, the ratio (aromatic compound represented by formula(1): lactam compound represented by formula (2)) is 30:70 to 80:20, morepreferably 35:65 to 76:24, still more preferably 40:60 to 73:27, yetmore preferably 45:55 to 70:30.

In the present invention, the solvent used in the cleaning agentcomposition is limited to an organic solvent, whereby metalliccontamination, metallic corrosion, etc. attributable to water aresuppressed, to thereby suitably clean a substrate at highreproducibility. Thus, the cleaning agent composition of the presentinvention generally contains only an organic solvent as a solvent. Asused herein, the expression “only an organic solvent” refers to theintended component of the solvent being formed of only an organicsolvent, and does not exclude the presence of water unavoidablycontained in the organic solvent and in other components.

In one preferred embodiment of the present invention, the organicsolvent of the cleaning agent composition of the present inventionconsists of the aromatic compound represented by formula (1) and thelactam compound represented by formula (2).

In the present invention, the tetrahydrocarbylammonium fluoride isdissolved in the solvent contained in the cleaning agent composition.

The cleaning agent composition of the present invention is prepared bymixing the tetrahydrocarbylammonium fluoride, the aromatic compoundrepresented by formula (1), the lactam compound represented by formula(2), and other optional components. These ingredients may be mixed inany chronological order, so long as problematic phenomena impeding theattainment of the objects of the present invention (e.g., precipitationand liquid phase separation) do not occur. That is, a part of theingredients of the cleaning agent composition may be mixed in advance,followed by mixing of the other ingredients. Alternatively, all theingredients may be mixed through a single mixing operation. If required,the cleaning agent composition may be filtered. Further, in the casewhere a certain ingredient has hygroscopicity, deliquescency, or thelike, the entire or a part of the steps of preparing the cleaning agentcomposition may be conducted under inert gas.

The above-described cleaning agent composition of the present inventionexerts excellent cleansability to a polysiloxane adhesive and attains ahigh cleaning speed and an excellent cleaning persistency.

Specifically, the cleaning speed is determined as an etching rate[μm/min], which is determined by measuring a decrease in the layer(film) thickness of an adhesive layer obtained from an adhesivecomposition of interest after contact with the cleaning agentcomposition of the present invention for 5 minutes at room temperature(23° C.) and dividing the decrease in the layer thickness by the timerequired for cleaning. The etching rate is generally 5.0 [μm/min] orgreater, 7.0 [μm/min] or greater in a preferred embodiment, 7.5 [μm/min]or greater in a more preferred embodiment, 8.0 [μm/min] or greater in astill more preferred embodiment, and 9.0 [μm/min] or greater in a yetmore preferred embodiment.

The cleaning persistency of the cleaning agent composition of thepresent invention is assessed by the time for dissolving 1 g of anadhesive solid obtained from an adhesive composition through contactwith the cleaning agent composition (2 g) at room temperature (23° C.).The cleaning persistency is generally 12 to 24 hours for substantialdissolution of the adhesive solid, 2 to 12 hours for completedissolution of the adhesive solid in a preferred embodiment, and 1 to 2hours for complete dissolution of the adhesive solid in a more preferredembodiment.

According to the present invention, a polysiloxane adhesive remaining ona substrate (e.g., a semiconductor substrate) is removed by use of theabove-described cleaning agent composition, whereby the substrate can becleaned in a short period of time. Thus, high-efficiency (favorable)cleaning of a substrate (e.g., a semiconductor substrate) can beachieved.

The cleaning agent composition of the present invention is used forsurface-cleaning of various substrates including semiconductorsubstrates. The cleaning target is not limited to a siliconsemiconductor substrate, and various substrates may be cleaned. Examplesof such substrates (cleaning targets) include a germanium substrate, agallium arsenide substrate, a gallium phosphide substrate, a galliumaluminum arsenide substrate, an aluminum-plated silicon substrate, acopper-plated silicon substrate, a silver-plated silicon substrate, agold-plated silicon substrate, a titanium-plated silicon substrate, asilicon nitride film-coated silicon substrate, a silicon oxidefilm-coated silicon substrate, a polyimide film-coated siliconsubstrate, a glass substrate, a quartz substrate, a liquid crystalsubstrate, and an organic EL substrate.

One suitable mode of use of the cleaning agent composition of thepresent invention in semiconductor processing is use thereof in a methodfor producing a thinned substrate employed in semiconductor packagingtechniques such as TSV.

More specifically, the cleaning agent composition of the presentinvention is used as a cleaning agent composition in a production methodincluding a first step of producing a laminate including a semiconductorsubstrate, a support substrate, and an adhesive layer formed from anadhesive composition; a second step of processing the semiconductorsubstrate of the produced laminate; a third step of debonding thesemiconductor substrate after processing; and a fourth step of removingan adhesive residue remaining on the debonded semiconductor substratewith a cleaning agent composition.

Typically, the adhesive composition used in the first step for formingan adhesive layer may be at least one species selected from among asilicone adhesive, an acrylic resin adhesive, an epoxy resin adhesive, apolyamide adhesive, a polystyrene adhesive, a polyimide adhesive, and aphenolic resin adhesive. Particularly for removing a polysiloxaneadhesive, the cleaning agent composition of the present invention iseffectively used. Among polysiloxane adhesives, the cleaning agentcomposition of the present invention is effective for removing a residueoriginating from a polysiloxane adhesive containing a component (A)which is cured through hydrosilylation.

Thus, next will be described a method for producing a thinned substrateby use of a polysiloxane adhesive (adhesive composition) containing acomponent (A) which is cured through hydrosilylation, and the cleaningagent composition of the present invention. However, needless to say,the present invention is not limited to the production method.

Firstly, there will be described the first step of producing a laminateincluding a semiconductor substrate, a support substrate, and anadhesive layer formed from an adhesive composition.

The component (A) which is contained in the adhesive composition andwhich is cured through hydrosilylation contains, for example, apolysiloxane (A1) having one or more units selected from the groupconsisting of a siloxane unit represented by SiO₂ (unit Q), a siloxaneunit represented by R¹R²R³SiO_(1/2) (unit M), a siloxane unitrepresented by R⁴R⁵SiO_(2/2) (unit D), and a siloxane unit representedby R⁶SiO_(3/2) (unit T), and a platinum group metal catalyst (A²);wherein the polysiloxane (A1) contains a polyorganosiloxane (a1) havingone or more units selected from the group consisting of a siloxane unitrepresented by SiO₂ (unit Q′), a siloxane unit represented byR^(1′)R^(2′)R^(3′)SiO_(1/2) (unit M′), a siloxane unit represented byR^(4′)R^(5′)SiO_(2/2) (unit D′), and a siloxane unit represented byR^(6′)SiO_(3/2) (unit T′), and at least one unit selected from the groupconsisting of unit M′, unit D′, and unit T′, and

-   -   a polyorganosiloxane (a2) having one or more units selected from        the group consisting of a siloxane unit represented by SiO₂        (unit Q″), a siloxane unit represented by        R^(1″)R^(2″)R^(3″)SiO_(1/2) (unit M″), a siloxane unit        represented by R^(4″)R^(5″)SiO_(2/2) (unit D″), and a siloxane        unit represented by R^(6″)SiO_(3/2) (unit T″), and at least one        unit selected from the group consisting of unit M″, unit D″, and        unit T″.

Each of R¹ to R⁶ is a group or an atom bonded to a silicon atom andrepresents an alkyl group, an alkenyl group, or a hydrogen atom.

Each of R^(1′) to R^(6′) is a group bonded to a silicon atom andrepresents an alkyl group or an alkenyl group, and at least one ofR^(1′) to R^(6′) is an alkenyl group.

Each of R^(1″) to R^(6″) is a group or an atom bonded to a silicon atomand represents an alkyl group or a hydrogen atom, and at least one ofR^(1″) to R^(6″) is a hydrogen atom.

The alkyl group may be linear-chain, branched-chain, or cyclic. However,a linear-chain alkyl group and a branched-chain alkyl group arepreferred. No particular limitation is imposed on the number of carbonatoms thereof, and the number of carbon atoms is generally 1 to 40,preferably 30 or less, more preferably 20 or less, still more preferably10 or less.

Specific examples of the linear-chain or branched-chain alkyl groupinclude, but are not limited to, methyl, ethyl, n-propyl, i-propyl,n-butyl, i-butyl, s-butyl, t-butyl, n-pentyl, 1-methyl-n-butyl,2-methyl-n-butyl, 3-methyl-n-butyl, 1,1-dimethyl-n-propyl,1,2-dimethyl-n-propyl, 2,2-dimethyl-n-propyl, 1-ethyl-n-propyl, n-hexyl,1-methyl-n-pentyl, 2-methyl-n-pentyl, 3-methyl-n-pentyl,4-methyl-n-pentyl, 1,1-dimethyl-n-butyl, 1,2-dimethyl-n-butyl,1,3-dimethyl-n-butyl, 2,2-dimethyl-n-butyl, 2,3-dimethyl-n-butyl,3,3-dimethyl-n-butyl, 1-ethyl-n-butyl, 2-ethyl-n-butyl,1,1,2-trimethyl-n-propyl, 1,2,2-trimethyl-n-propyl,1-ethyl-1-methyl-n-propyl, and 1-ethyl-2-methyl-n-propyl.

Of these, methyl is preferred.

Specific examples of the cyclic alkyl group include, but are not limitedto, cycloalkyl groups such as cyclopropyl, cyclobutyl,1-methyl-cyclopropyl, 2-methyl-cyclopropyl, cyclopentyl,1-methyl-cyclobutyl, 2-methyl-cyclobutyl, 3-methyl-cyclobutyl,1,2-dimethyl-cyclopropyl, 2,3-dimethyl-cyclopropyl, 1-ethyl-cyclopropyl,2-ethyl-cyclopropyl, cyclohexyl, 1-methyl-cyclopentyl,2-methyl-cyclopentyl, 3-methyl-cyclopentyl, 1-ethyl-cyclobutyl,2-ethyl-cyclobutyl, 3-ethyl-cyclobutyl, 1,2-dimethyl-cyclobutyl,1,3-dimethyl-cyclobutyl, 2,2-dimethyl-cyclobutyl,2,3-dimethyl-cyclobutyl, 2,4-dimethyl-cyclobutyl,3,3-dimethyl-cyclobutyl, 1-n-propyl-cyclopropyl, 2-n-propyl-cyclopropyl,1-1-propyl-cyclopropyl, 2-1-propyl-cyclopropyl,1,2,2-trimethyl-cyclopropyl, 1,2,3-trimethyl-cyclopropyl,2,2,3-trimethyl-cyclopropyl, 1-ethyl-2-methyl-cyclopropyl,2-ethyl-1-methyl-cyclopropyl, 2-ethyl-2-methyl-cyclopropyl, and2-ethyl-3-methyl-cyclopropyl; and bicycloalkyl groups such asbicyclobutyl, bicyclopentyl, bicyclohexyl, bicycloheptyl, bicyclooctyl,bicyclononyl, and bicyclodecyl.

The alkenyl group may be linear-chain or branched-chain. No particularlimitation is imposed on the number of carbon atoms thereof, and thenumber of carbon atoms is generally 2 to 40, preferably 30 or less, morepreferably 20 or less, still more preferably 10 or less.

Specific examples of the alkenyl group include, but are not limited to,ethenyl, 1-propenyl, 2-propenyl, 1-methyl-1-ethenyl, 1-butenyl,2-butenyl, 3-butenyl, 2-methyl-1-propenyl, 2-methyl-2-propenyl,1-ethylethenyl, 1-methyl-1-propenyl, 1-methyl-2-propenyl, 1-pentenyl,2-pentenyl, 3-pentenyl, 4-pentenyl, 1-n-propylethenyl,1-methyl-1-butenyl, 1-methyl-2-butenyl, 1-methyl-3-butenyl,2-ethyl-2-propenyl, 2-methyl-1-butenyl, 2-methyl-2-butenyl,2-methyl-3-butenyl, 3-methyl-1-butenyl, 3-methyl-2-butenyl,3-methyl-3-butenyl, 1,1-dimethyl-2-propenyl, 1-1-propylethenyl,1,2-dimethyl-1-propenyl, 1,2-dimethyl-2-propenyl, 1-cyclopentenyl,2-cyclopentenyl, 3-cyclopentenyl, 1-hexenyl, 2-hexenyl, 3-hexenyl,4-hexenyl, 5-hexenyl, 1-methyl-1-pentenyl, 1-methyl-2-pentenyl,1-methyl-3-pentenyl, 1-methyl-4-pentenyl, 1-n-butylethenyl,2-methyl-1-pentenyl, 2-methyl-2-pentenyl, 2-methyl-3-pentenyl,2-methyl-4-pentenyl, 2-n-propyl-2-propenyl, 3-methyl-1-pentenyl,3-methyl-2-pentenyl, 3-methyl-3-pentenyl, 3-methyl-4-pentenyl,3-ethyl-3-butenyl, 4-methyl-1-pentenyl, 4-methyl-2-pentenyl,4-methyl-3-pentenyl, 4-methyl-4-pentenyl, 1,1-dimethyl-2-butenyl,1,1-dimethyl-3-butenyl, 1,2-dimethyl-1-butenyl, 1,2-dimethyl-2-butenyl,1,2-dimethyl-3-butenyl, 1-methyl-2-ethyl-2-propenyl, 1-s-butylethenyl,1,3-dimethyl-1-butenyl, 1,3-dimethyl-2-butenyl, 1,3-dimethyl-3-butenyl,1-1-butylethenyl, 2,2-dimethyl-3-butenyl, 2,3-dimethyl-1-butenyl,2,3-dimethyl-2-butenyl, 2,3-dimethyl-3-butenyl, 2-1-propyl-2-propenyl,3,3-dimethyl-1-butenyl, 1-ethyl-1-butenyl, 1-ethyl-2-butenyl,1-ethyl-3-butenyl, 1-n-propyl-1-propenyl, 1-n-propyl-2-propenyl,2-ethyl-1-butenyl, 2-ethyl-2-butenyl, 2-ethyl-3-butenyl,1,1,2-trimethyl-2-propenyl, 1-t-butylethenyl,1-methyl-1-ethyl-2-propenyl, 1-ethyl-2-methyl-1-propenyl,1-ethyl-2-methyl-2-propenyl, 1-1-propyl-1-propenyl,1-1-propyl-2-propenyl, 1-methyl-2-cyclopentenyl,1-methyl-3-cyclopentenyl, 2-methyl-1-cyclopentenyl,2-methyl-2-cyclopentenyl, 2-methyl-3-cyclopentenyl,2-methyl-4-cyclopentenyl, 2-methyl-5-cyclopentenyl,2-methylene-cyclopentyl, 3-methyl-1-cyclopentenyl,3-methyl-2-cyclopentenyl, 3-methyl-3-cyclopentenyl,3-methyl-4-cyclopentenyl, 3-methyl-5-cyclopentenyl,3-methylene-cyclopentyl, 1-cyclohexenyl, 2-cyclohexenyl, and3-cyclohexenyl.

Of these, ethenyl and 2-propenyl are preferred.

As described above, the polysiloxane (A1) includes thepolyorganosiloxane (a1) and the polyorganosiloxane (a2). In curing, thealkenyl group present in the polyorganosiloxane (a1) and the hydrogenatom (Si—H group) present in the polyorganosiloxane (a2) form across-linking structure through hydrosilylation in the presence of theplatinum group metal catalyst (A2).

The polyorganosiloxane (a1) has one or more units selected from thegroup consisting of unit Q′, unit M′, unit D′, and unit T′, and at leastone unit selected from the group consisting of unit M′, unit D′, andunit T′. Two or more polyorganosiloxanes satisfying the above conditionsmay be used in combination as the polyorganosiloxane (a1).

Examples of preferred combinations of two or more units selected fromthe group consisting of unit Q′, unit M′, unit D′, and unit T′ include,but are not limited to, (unit Q′ and unit M′), (unit D′ and unit M′),(unit T′ and unit M′), and (unit Q′, unit T′, and unit M′).

In the case where the polyorganosiloxane (a1) includes two or morepolyorganosiloxanes, examples of preferred combinations include, but arenot limited to, (unit Q′ and unit M′)+(unit D′ and unit M′); (unit T′and unit M′)+(unit D′ and unit M′); and (unit Q′, unit T′, and unitM′)+(unit T′ and unit M′).

The polyorganosiloxane (a2) has one or more units selected from thegroup consisting of unit Q″, unit M″, unit D″, and unit T″, and at leastone unit selected from the group consisting of unit M″, unit D″, andunit T″. Two or more polyorganosiloxanes satisfying the above conditionsmay be used in combination as the polyorganosiloxane (a2).

Examples of preferred combinations of two or more units selected fromthe group consisting of unit Q″, unit M″, unit D″, and unit T″ include,but are not limited to, (unit M″ and unit D″), (unit Q″ and unit M″),and (unit Q″, unit T″, and unit M″).

The polyorganosiloxane (a1) is formed of siloxane units in which analkyl group and/or an alkenyl group is bonded to a silicon atom. Thealkenyl group content of the entire substituents R^(1′) to R^(6′) ispreferably 0.1 mol % to 50.0 mol %, more preferably 0.5 mol % to 30.0mol %, and the remaining R^(1′) to R^(6′) may be alkyl groups.

The polyorganosiloxane (a2) is formed of siloxane units in which analkyl group and/or a hydrogen atom is bonded to a silicon atom. Thehydrogen atom content of the entire substituents or atoms R^(1″) toR^(6″) is preferably 0.1 mol % to 50.0 mol %, more preferably 10.0 mol %to 40.0 mol %, and the remaining R^(1″) to R^(6″) may be alkyl groups.

The polysiloxane (A1) includes the polyorganosiloxane (a1) and thepolyorganosiloxane (a2). In one preferred embodiment of the presentinvention, the ratio by mole of alkenyl groups present in thepolyorganosiloxane (a1) to hydrogen atoms forming Si—H bonds present inthe polyorganosiloxane (a2) is 1.0:0.5 to 1.0:0.66.

The weight average molecular weight of each of the polyorganosiloxane(a1) and the polyorganosiloxane (a2) are generally 500 to 1,000,000,preferably 5,000 to 50,000.

Meanwhile, weight average molecular weight may be determined by meansof, for example, a GPC apparatus (EcoSEC, HLC-8320GPC, products of TosohCorporation) and GPC columns (Shodex(registered trademark), KF-803L,KF-802, and KF-801, products of Showa Denko K.K.) at a columntemperature of 40° C. and a flow rate of 1.0 mL/min by use oftetrahydrofuran as an eluent (extraction solvent) and polystyrene(product of Sigma-Aldrich) as a standard substance.

The polyorganosiloxane (a1) and the polyorganosiloxane (a2) contained inthe adhesive composition react with each other via hydrosilylation, tothereby form a cured film. Thus, the curing mechanism differs from themechanism of curing mediated by, for example, silanol groups. Therefore,neither of the siloxanes of the present invention is required to have asilanol group or a functional group forming a silanol group throughhydrolysis (e.g., an alkyloxy group).

The component (A) contains the platinum group metal catalyst (A2).

The platinum-based metallic catalyst is used to acceleratehydrosilylation between alkenyl groups of the polyorganosiloxane (a1)and Si—H groups of the polyorganosiloxane (a2).

Specific examples of the platinum-based metallic catalyst include, butare not limited to, platinum catalysts such as platinum black,platinum(II) chloride, chloroplatinic acid, a reaction product ofchloroplatinic acid and a monohydric alcohol, a chloroplatinicacid-olefin complex, and platinum bis(acetoacetate).

Examples of the platinum-olefin complex include, but are not limited to,a complex of platinum with divinyltetramethyldisiloxane.

The amount of platinum group metal catalyst (A2) is generally 1.0 to50.0 ppm, with respect to the total amount of polyorganosiloxane (a1)and polyorganosiloxane (a2).

The component (A) may contain a polymerization inhibitor (A3). Throughincorporation of the polymerization inhibitor into the adhesivecomposition, heat curing during bonding can be suitably controlled,whereby an adhesive composition which can provide an adhesive layerhaving an excellent bonding/debonding property can be produced at highreproducibility.

No particular limitation is imposed on the polymerization inhibitor, solong as it can suppress the progress of hydrosilylation. Specificexamples of the polymerization inhibitor include, but are not limitedto, optionally aryl group-substituted alkynylalkyl alcohols such as1-ethynyl-1-cyclohexanol and 1,1-diphenyl-2-propyn-1-ol.

Generally, the amount of polymerization inhibitor with respect to thepolyorganosiloxane (a1) and the polyorganosiloxane (a2) is 1,000.0 ppmor more from the viewpoint of attaining the effect, and 10,000.0 ppm orless from the viewpoint of preventing excessive suppression ofhydrosilylation.

The adhesive composition may contain a component (B) containing at leastone species selected from the group consisting of a component containingan epoxy-modified polyorganosiloxane, a component containing amethyl-group-containing polyorganosiloxane, and a component containing aphenyl-group-containing polyorganosiloxane. Through incorporation ofsuch a component (B) into the adhesive composition, the formed adhesivelayer can be suitably peeled off at high reproducibility.

The epoxy-modified polyorganosiloxane includes, for example, such asiloxane containing a siloxane unit represented by R²¹⁰R²²⁰SiO_(2/2)(unit D²⁰⁰), preferably a siloxane containing a siloxane unitrepresented by R¹¹R¹²SiO_(2/2) (unit) D¹⁰).

R¹¹ is a group bonded to a silicon atom and represents an alkyl group,and R¹² is a group bonded to a silicon atom and represents an epoxygroup or an organic group containing an epoxy group. Specific examplesof the alkyl group include those as exemplified above.

Also, the epoxy group in the organic group containing an epoxy group maybe an independent epoxy group which does not condense with another ringstructure, or may be an epoxy group forming a condensed ring withanother ring structure (e.g., a 1,2-epoxycyclohexyl group).

Specific examples of the organic group containing an epoxy groupinclude, but are not limited to, 3-glycidoxypropyl and2-(3,4-epoxycyclohexyl)ethyl.

In the present invention, examples of preferred epoxy-modifiedpolyorganosiloxanes include, but are not limited to, epoxy-modifiedpolydimethylsiloxane.

The epoxy-modified polyorganosiloxane contains the aforementionedsiloxane unit (unit D¹⁰), but may also contain the aforementioned unitQ, unit M and/or unit T, in addition to unit D¹⁰.

In one preferred embodiment, specific examples of the epoxy-modifiedpolyorganosiloxane include polyorganosiloxane formed only of unit D¹⁰,polyorganosiloxane formed of unit D¹⁰ and unit Q, polyorganosiloxaneformed of unit D¹⁰ and unit M, polyorganosiloxane formed of unit D¹⁰ andunit T, polyorganosiloxane formed of unit D¹⁰, unit Q, and unit M,polyorganosiloxane formed of unit D¹⁰, unit M, and unit T, andpolyorganosiloxane formed of unit D¹⁰, unit Q, unit M, and unit T.

The epoxy-modified polyorganosiloxane is preferably an epoxy-modifiedpolydimethylsiloxane having an epoxy value of 0.1 to 5. The weightaverage molecular weight thereof is generally 1,500 to 500,000, butpreferably 100,000 or lower, for the purpose of suppression ofdeposition in the adhesive composition.

Specific examples of the epoxy-modified polyorganosiloxane include, butare not limited to, CMS-227 (product of Gelest Inc., weight averagemolecular weight: 27,000) represented by formula (A-1), ECMS-327(product of Gelest Inc., weight average molecular weight: 28,800)represented by formula (A-2), KF-101 (product of Shin-Etsu Chemical Co.,Ltd., weight average molecular weight: 31,800) represented by formula(A-3), KF-1001 (product of Shin-Etsu Chemical Co., Ltd., weight averagemolecular weight: 55,600) represented by formula (A-4), KF-1005 (productof Shin-Etsu Chemical Co., Ltd., weight average molecular weight:11,500) represented by formula (A-5), X-22-343 (product of Shin-EtsuChemical Co., Ltd., weight average molecular weight: 2,400) representedby formula (A-6), BY16-839 (product of Dow Corning, weight averagemolecular weight: 51,700) represented by formula (A-7), and ECMS-327(product of Gelest Inc., weight average molecular weight: 28,800)represented by formula (A-8).

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units. R representsa C1 to C10 alkylene group.)

(Each of m and n represents the number of repeating units. R representsa C1 to C10 alkylene group.)

(Each of m, n and o represents the number of repeating units. Rrepresents a C1 to C10 alkylene group.)

(Each of m and n represents the number of repeating units. R representsa C1 to C10 alkylene group.)

(Each of m and n represents the number of repeating units. R representsa C1 to C10 alkylene group.)

(Each of m and n represents the number of repeating units.)

The methyl-group-containing polyorganosiloxane includes, for example, asiloxane containing a siloxane unit represented by R²¹⁰R²²⁰SiO_(2/2)(unit D²⁰⁰), preferably a siloxane containing a siloxane unitrepresented by R²¹R²¹SiO_(2/2) (unit D²⁰).

Each of R²¹⁰ and R²²⁰ is a group bonded to a silicon atom and representsan alkyl group. At least one of R²¹⁰ and R²²⁰ is a methyl group.Specific examples of the alkyl group include those as exemplified above.

R²¹ is a group bonded to a silicon atom and represents an alkyl group.Specific examples of the alkyl group include those as exemplified above.R²¹ is preferably a methyl group.

Examples of preferred methyl-group-containing polyorganosiloxanesinclude, but are not limited to, polydimethylsiloxane.

The methyl-group-containing polyorganosiloxane contains theaforementioned siloxane unit (unit D²⁰⁰ or unit D²⁰), but may alsocontain the aforementioned unit Q, unit M and/or unit T, in addition tounit D²⁰⁰ or unit D²⁰.

In one embodiment, specific examples of the methyl-group-containingpolyorganosiloxane include polyorganosiloxane formed only of unit D²⁰⁰,polyorganosiloxane formed of unit D²⁰⁰ and unit Q, polyorganosiloxaneformed of unit D²⁰⁰ and unit M, polyorganosiloxane formed of unit D²⁰⁰and unit T, polyorganosiloxane formed of unit D²⁰⁰, unit Q, and unit M,polyorganosiloxane formed of unit D²⁰⁰, unit M, and unit T, andpolyorganosiloxane formed of unit D²⁰⁰, unit Q, unit M, and unit T.

In one preferred embodiment, specific examples of themethyl-group-containing polyorganosiloxane include polyorganosiloxaneformed only of unit D²⁰, polyorganosiloxane formed of unit D²⁰ and unitQ, polyorganosiloxane formed of unit D²⁰ and unit M, polyorganosiloxaneformed of unit D²⁰ and unit T, polyorganosiloxane formed of unit D²⁰,unit Q, and unit M, polyorganosiloxane formed of unit D²⁰, unit M, andunit T, and polyorganosiloxane formed of unit D²⁰, unit Q, unit M, andunit T.

The viscosity of the methyl-group-containing polyorganosiloxane isgenerally 1,000 to 2,000,000 mm²/s, preferably 10,000 to 1,000,000mm²/s. The methyl-group-containing polyorganosiloxane is typicallydimethylsilicone oil formed of polydimethylsiloxane. The value of theviscosity is a kinematic viscosity (cSt (=mm²/s)). The kinematicviscosity may be measured by means of a kinematic viscometer.Alternatively, the kinematic viscosity may also be calculated bydividing viscosity (mPa·s) by density (g/cm³). In other words, thekinematic viscosity may be determined from a viscosity as measured at25° C. by means of an E-type rotational viscometer and a density. Thecalculation formula is kinematic viscosity (mm²/s)=viscosity(mPa·s)/density (g/cm³).

Specific examples of the methyl-group-containing polyorganosiloxaneinclude, but are not limited to, WACKER(registered trademark) SILICONEFLUID AK series (products of WACKER) and dimethylsilicone oils (KF-96L,KF-96A, KF-96, KF-96H, KF-69, KF-965, and KF-968) and cyclicdimethylsilicone oil (KF-995) (products of Shin-Etsu Chemical Co.,Ltd.).

Examples of the phenyl-group-containing polyorganosiloxane include asiloxane containing a siloxane unit represented by R³¹R³²SiO_(2/2) (unitD³⁰).

R³¹ is a group bonded to a silicon atom and represents a phenyl group oran alkyl group, and R³² is a group bonded to a silicon atom andrepresents a phenyl group. Specific examples of the alkyl group includethose as exemplified above. R³¹ is preferably a methyl group.

The phenyl-group-containing polyorganosiloxane contains theaforementioned siloxane unit (unit D³⁰), but may also contain theaforementioned unit Q, unit M and/or unit T, in addition to unit D³⁰.

In one preferred embodiment, specific examples of thephenyl-group-containing polyorganosiloxane include polyorganosiloxaneformed only of unit D³⁰, polyorganosiloxane formed of unit D³⁰ and unitQ, polyorganosiloxane formed of unit D³⁰ and unit M, polyorganosiloxaneformed of unit D³⁰ and unit T, polyorganosiloxane formed of unit D³⁰,unit Q, and unit M, polyorganosiloxane formed of unit D³⁰, unit M, andunit T, and polyorganosiloxane formed of unit D³⁰, unit Q, unit M, andunit T.

The weight average molecular weight of the phenyl-group-containingpolyorganosiloxane is generally 1,500 to 500,000, but preferably 100,000or lower, for the purpose of suppression of deposition in the adhesivecomposition and for other reasons.

Specific examples of the phenyl-group-containing polyorganosiloxaneinclude, but are not limited to, PMM-1043 (product of Gelest Inc.,weight average molecular weight: 67,000, viscosity: 30,000 mm²/s)represented by formula (C-1), PMM-1025 (product of Gelest Inc., weightaverage molecular weight: 25,200, viscosity: 500 mm²/s) represented byformula (C-2), KF50-3000CS (product of Shin-Etsu Chemical Co., Ltd.,weight average molecular weight: 39,400, viscosity: 3,000 mm²/s)represented by formula (C-3), TSF431 (product of MOMENTIVE, weightaverage molecular weight: 1,800, viscosity: 100 mm²/s) represented byformula (C-4), TSF433 (product of MOMENTIVE, weight average molecularweight: 3,000, viscosity: 450 mm²/s) represented by formula (C-5),PDM-0421 (product of Gelest Inc., weight average molecular weight:6,200, viscosity: 100 mm²/s) represented by formula (C-6), and PDM-0821(product of Gelest Inc., weight average molecular weight: 8,600,viscosity: 125 mm²/s) represented by formula (C-7).

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

(Each of m and n represents the number of repeating units.)

The polysiloxane adhesive composition contains the components (A) and(B) at any compositional ratio. In consideration of the balance betweenbonding performance and debonding performance, the compositional ratio(mass %) of component (A) to component (B) is preferably 99.995:0.005 to30:70, more preferably 99.9:0.1 to 75:25.

For the purpose of adjusting the viscosity or for other reasons, theadhesive composition may contain a solvent. Specific examples of thesolvent include, but are not limited to, an aliphatic hydrocarbon, anaromatic hydrocarbon, and a ketone.

More specific examples of the solvent include, but are not limited to,hexane, heptane, octane, nonane, decane, undecane, dodecane,isododecane, menthane, limonene, toluene, xylene, mesitylene, cumene,MIBK (methyl isobutyl ketone), butyl acetate, diisobutyl ketone,2-octanone, 2-nonanone, and 5-nonanone. These solvents may be usedsingly or in combination of two or more species.

In the case where the adhesive composition contains a solvent, thesolvent content is appropriately adjusted in consideration of a targetviscosity of the adhesive composition, the application method to beemployed, the thickness of the formed thin film, etc. The solventcontent of the entire composition is about 10 to about 90 mass %.

The adhesive composition generally has a viscosity (25° C.) of 500 to20,000 mPa·s, preferably 1,000 to 5,000 mPa·s. The viscosity may becontrolled by modifying the type and formulation of the organic solventused, the film-forming component concentration, etc., in considerationof various factors such as the coating method employed and the targetfilm thickness. Notably, the term “film-forming component” used in thepresent invention refers to any component other than solvent.

The adhesive composition used in the present invention may be producedby mixing film-forming components with solvent. However, in the casewhere no solvent is used, the adhesive composition used in the presentinvention may be produced by mixing film-forming components.

The first step specifically includes a primary step and a subsequentstep. In the primary step, the adhesive composition is applied onto asurface of the semiconductor substrate or the support substrate, tothereby form an adhesive coating layer. In the subsequent step, thesemiconductor substrate is adhered to the support substrate by themediation of the adhesive coating layer, and a load is applied to thesemiconductor substrate and the support substrate in a thicknessdirection, to thereby closely adhere the semiconductor substrate, theadhesive coating layer, and the support substrate, while at least one ofa heat treatment and a reduced pressure treatment is performed. Then, apost-heat treatment is performed. Through the post-heat treatment in thesubsequent step, the adhesive coating layer is suitably cured in a finalstage to form an adhesive layer. Thus, a laminate is provided.

In one embodiment, the semiconductor substrate is a wafer, and thesupport substrate is a support. The adhesive composition may be appliedto either of the semiconductor or support substrate, or both of thesemiconductor and support substrates.

No particular limitation is imposed on the wafer, and an example of thewafer is a silicon wafer or a glass wafer having a diameter of about 300mm and a thickness of about 770 μm.

No particular limitation is imposed on the support (carrier). Examplesof the support include, but are not limited to, a silicon wafer having adiameter of about 300 mm and a thickness of about 700 μm.

The thickness of the aforementioned adhesive coating layer is generally5 to 500 μm. However, the thickness is preferably 10 μm or greater, morepreferably 20 μm or greater, still more preferably 30 μm or greater,from the viewpoint of maintaining the film strength, and it ispreferably 200 μm or less, more preferably 150 μm or less, still morepreferably 120 μm or less, yet more preferably 70 μm or less, from theviewpoint of avoiding variation in uniformity of the film thickness.

No particular limitation is imposed on the application method, and spincoating is generally employed. In an alternative method, a coating filmis formed through spin coating or a similar technique, and thesheet-form coating film is attached. The concepts of the applicationmethod and the coating film of the invention also encompass thealternative method and coating film.

The heating temperature is generally 80° C. or higher, preferably 150°C. or lower, from the viewpoint of prevention of excessive curing. Thetime of heating is generally 30 seconds or longer, preferably 1 minuteor longer, for securing temporary bonding performance. Also, the heatingtime is generally 10 minutes or shorter, preferably 5 minutes orshorter, from the viewpoint of suppressing deterioration of the adhesivelayer and other members.

In the reduced pressure treatment, the two substrates and the adhesivecoating layer disposed therebetween are placed in an atmosphere at 10 Pato 10,000 Pa. The time of the reduced pressure treatment is generally 1to 30 minutes.

In one preferred embodiment of the present invention, the two substratesand the adhesive coating layer disposed therebetween are bonded togetherpreferably through a heat treatment, more preferably through a heattreatment in combination with a reduced pressure treatment.

No particular limitation is imposed on the load which is applied to thesemiconductor substrate and the support substrate in a thicknessdirection, so long as the semiconductor substrate, the supportsubstrate, and the layer therebetween are not damaged, and theseelements are closely adhered. The load is generally 10 to 1,000 N.

The temperature of post-heating is preferably 120° C. or higher from theviewpoint of attaining sufficient curing rate, and preferably 260° C. orlower from the viewpoint of preventing deterioration of the substratesand the adhesives. The heating time is generally 1 minute or longer fromthe viewpoint of achieving suitable joining of a wafer through curing,preferably 5 minutes or longer from the viewpoint of, for example,stability in physical properties of the adhesives. Also, the heatingtime is generally 180 minutes or shorter, preferably 120 minutes orshorter, from the viewpoint of avoiding, for example, an adverse effecton the adhesive layers due to excessive heating. Heating may beperformed by means of a hot plate, an oven, or the like. Notably, apurpose of performing post-heating is to, for example, more suitablycure the component (A).

There will next be described the second step for processing thesemiconductor substrate of the laminate produced through theaforementioned method.

One example of the processing applied to the laminate used in thepresent invention is processing of a surface opposite thecircuit-furnished surface of the semiconductor substrate. Typically, theprocessing is a thinning of a wafer by polishing (grinding) the backsidethereof. Thereafter, through silicon vias (TSVs) and the like are formedby use of the thinned wafer, and the thinned wafer is removed from thesupport. A plurality of such wafers are stacked to form a waferlaminate, to thereby complete 3-dimensional mounting. Before or afterthe above process, a backside electrode and the like are formed on thewafer. When thinning of a wafer and the TSV process are performed, athermal load of 250 to 350° C. is applied to the laminate bonded to thesupport. The adhesive layer included in the laminate used in the presentinvention has heat resistance to the load.

In one specific embodiment, when the backside surface (a surfaceopposite the circuit-furnished surface) of a wafer having a diameter ofabout 300 mm and a thickness of about 770 μm is polished (ground), thethickness of the wafer can be reduced to about 80 μm to about 4 μm.

Next will be described the third step of debonding the semiconductorsubstrate formed of a semiconductor substrate after processing.

Examples of the laminate debonding method employed in the presentinvention include, but are not limited to, debonding with solvent,debonding with laser light, mechanical debonding by means of a machinemember having a sharp part, and peeling between a support and a wafer.Generally, debonding is performed after processing (e.g., thinning).

In the third step, the adhesive is not always removed while the adhesiveis firmly attached to the support substrate, and in some cases, a partof the adhesive may remain on the processed substrate. Thus, in thefourth step, the surface of the substrate on which the adhesive residueis attached is cleaned by use of the cleaning agent composition of thepresent invention. As a result, the adhesive remaining on the substratecan be satisfactorily removed.

Finally, the fourth step will be described. In the fourth step, theadhesive residue remaining on the debonded semiconductor substrateformed of a semiconductor substrate is removed by use of the cleaningagent composition.

The fourth step corresponds to removing the adhesive residue remainingon the debonded substrate by use of the cleaning agent composition ofthe present invention. In one specific procedure, a thinned substrate onwhich an adhesive remains is immersed in the cleaning agent compositionof the present invention and, if required, subjected to ultrasoniccleaning or the like, to thereby remove the adhesive residue.

When ultrasonic cleaning is employed, the cleaning conditions areappropriately determined in consideration of the surface state of thesubstrate. Generally, through ultrasonic cleaning at 20 kHz to 5 MHz for10 seconds to 30 minutes, the adhesive residue remaining on thesubstrate can be satisfactorily removed.

The method according to the present invention for producing a thinnedsubstrate includes the aforementioned first to fourth steps, but mayfurther include another step. For example, in the fourth step, beforecleaning with the cleaning agent composition of the present invention,if required, the substrate may be immersed in various solvents, orsubjected to tape peeling, to thereby remove the adhesive residue.

Notably, the aforementioned essential and claimed elements in the firstto fourth steps may be modified in various ways, so long as themodifications do not deviate from the scope of the present invention.

EXAMPLES

The present invention will next be described in detail by way ofExamples and Comparative Examples, which should not be construed aslimiting the invention thereto. The apparatuses employed in the presentinvention are as follows.

-   (1) Agitator: Planetary centrifugal mixer ARE-500 (product of Thinky    Corporation)-   (2) Viscometer: Rotary viscometer TVE-22H (product of Toki Sangyo    Co., Ltd)-   (3) Agitator: Mix Roter Variable 1-1186-12 (product of As One    Corporation)-   (4) Agitator H: Heating Rocking Mixer HRM-1 (product of As One    Corporation)-   (5) Contact-type film thickness meter: Wafer thickness meter WT-425    (product of Tokyo Seimitsu Co., Ltd.)

[1] Preparation of Adhesive Compositions Preparation Example 1

To a 600-mL agitation container dedicated for a planetary centrifugalmixer, there were added a base polymer formed of linear-chainpolydimethylsiloxane having vinyl groups (viscosity: 200 mPa·s) and anMQ resin having vinyl groups (product of WACKER Chemie AG) (a1) (150 g),linear-chain polydimethylsiloxane having Si—H groups (viscosity: 100mPa·s) (product of WACKER Chemie AG) (a2) (15.81 g), and1-ethynyl-1-cyclohexanol (product of WACKER Chemie AG) (A3) (0.17 g),and the resultant mixture was agitated by means of a planetarycentrifugal mixer for 5 minutes.

Separately, a platinum catalyst (product of WACKER Chemie AG) (A2) (0.33g) and linear-chain polydimethylsiloxane having vinyl groups (viscosity:1,000 mPa·s) (product of WACKER Chemie AG) (a1) (9.98 g) were added to a50-mL screw tube, and the contents were agitated for 5 minutes by meansof a planetary centrifugal mixer. A portion (0.52 g) of thethus-agitated mixture was added to the above mixture, and the resultantmixture was agitated for 5 minutes by means of a planetary centrifugalmixer. Finally, the product mixture was filtered through a nylon filter(300 mesh), to thereby prepare an adhesive composition having aviscosity of 9,900 mPa·s as determined by means of a rotary viscometer.

Preparation Example 2

To a 600-mL agitation container dedicated for a planetary centrifugalmixer, an MQ resin having vinyl groups (product of WACKER Chemie AG)(a1) (95 g), p-menthane (product of Nippon Terpene Chemicals, Inc.)(93.4 g) serving as a solvent, and 1,1-diphenyl-2-propyn-1-ol (productof Tokyo Chemical Industry Co., Ltd.) (0.41 g) were added, and theresultant mixture was agitated for 5 minutes by means of a planetarycentrifugal mixer.

To the thus-prepared mixture, there were added linear-chainpolydimethylsiloxane having Si—H groups (viscosity: 100 mPa·s) (productof WACKER Chemie AG) (a2), linear-chain polydimethylsiloxane havingvinyl groups (viscosity: 200 mPa·s) (product of WACKER Chemie AG) (a1)(29.5 g), polyorganosiloxane (viscosity: 1,000,000 mm²/s) (AK1000000,product of WACKER Chemie AG) (B), and 1-ethynyl-1-cyclohexanol (productof WACKER Chemie AG) (A3) (0.41 g), and the resultant mixture wasfurther agitated for 5 minutes by means of a planetary centrifugalmixer.

Separately, a platinum catalyst (product of WACKER Chemie AG) (A2) (0.20g) and linear-chain polydimethylsiloxane having vinyl groups (viscosity:1,000 mPa·s) (product of WACKER Chemie AG) (a1) (17.7 g) were added to a50-mL screw tube, and the contents were agitated for 5 minutes by meansof a planetary centrifugal mixer. A portion (14.9 g) of thethus-agitated mixture was added to the above mixture, and the resultantmixture was further agitated for 5 minutes by means of the planetarycentrifugal mixer. Finally, the product mixture was filtered through anylon filter (300 mesh), to thereby prepare an adhesive compositionhaving a viscosity of 4,600 mPa·s as determined by means of a rotaryviscometer.

[2] Preparation of Cleaning Agent Compositions Example 1

A solvent mixture of N-methyl-2-pyrrolidone (dehydrate) (product ofKanto Chemical Co., Inc.) (47.5 g) and mesitylene (product of TokyoChemical Industry Co., Ltd.) (47.5 g) was added to tetrabutylammoniumfluoride trihydrate (product of Kanto Chemical Co., Inc.) (5 g), and thethus-obtained mixture was agitated, to thereby prepare a cleaning agentcomposition.

Example 2

The procedure of Example 1 was repeated, except that 4-t-butyltoluene(product of Kanto Chemical Co., Inc.) was used instead of mesitylene, tothereby prepare a cleaning agent composition.

Comparative Example 1

The procedure of Example 1 was repeated, except thatN-methyl-2-pyrrolidone (dehydrate) (95 g) was used as a solvent, tothereby prepare a cleaning agent composition.

Comparative Example 2

The procedure of Example 1 was repeated, except that toluene (product ofKanto Chemical Co., Inc.) was used instead of mesitylene, to therebyprepare a cleaning agent composition.

Comparative Example 3

The procedure of Example 1 was repeated, except that o-xylene (productof Kanto Chemical Co., Inc.) was used instead of mesitylene, to therebyprepare a cleaning agent composition.

Comparative Example 4

The procedure of Example 1 was repeated, except that m-xylene (productof Kanto Chemical Co., Inc.) was used instead of mesitylene, to therebyprepare a cleaning agent composition.

Comparative Example 5

The procedure of Example 1 was repeated, except that p-xylene (productof Kanto Chemical Co., Inc.) was used instead of mesitylene, to therebyprepare a cleaning agent composition.

Comparative Example 6

The procedure of Example 1 was repeated, except that mesitylene (95 g)was used as a solvent, for preparing a cleaning agent composition.However, unsuccessfully, tetrabutylammonium fluoride trihydrate was notcompletely dissolved.

Comparative Example 7

A commercial silicone cleaner “KSR-1” (product of Kanto Chemical Co.,Inc.) was used as a cleaning liquid composition.

[3] Evaluation of Performance of Cleaning Agent Compositions

Generally, the excellent cleaning agent composition is required toexhibit such a high cleaning speed that it can dissolve an adhesiveresidue immediately after contact therewith, and excellent persistencyin cleaning speed. Thus, the following tests were performed. When atested cleaning agent composition exhibits both higher cleaning speedand more excellent persistency in cleaning performance, more effectivecleaning can be expected.

[3-1] Determination of Etching Rate

Each of the prepared cleaning agent compositions was evaluated in termsof cleaning speed by measuring the etching rate. Specifically, theadhesive composition obtained in Preparation Example 1 was applied ontoa 12-inch silicon wafer by means of a spin coater so as to adjust thecoating thickness to 100 μm, and cured at 150° C. for 15 minutes, then190° C. for 10 minutes. The thus-coated wafer was cut into square chips(4 cm×4 cm), and the layer (film) thickness of one of the chips wasmeasured by means of a contact-type film thickness meter. Thereafter,the chip was placed in a 9-cm Petri dish made of stainless steel, andthe cleaning agent composition (7 mL) was added, followed by closing thedish. The closed Petri dish was placed on Agitator H, and the chip wascleaned through agitation at 23° C. for 5 minutes. After cleaning, thechip was removed and washed with isopropanol and pure water, and thendry-baked at 150° C. for 1 minute. The layer (film) thickness of thechip was measured again by means of the contact-type film thicknessmeter. Through dividing the decrease in layer (film) thickness aftercleaning by the cleaning time, etching rate [μm/min] was calculated. Theetching rate was employed as an index for cleaning performance. Table 1shows the results.

[3-2] Evaluation of Dissolution Property

For determining the persistency in cleaning performance of each of theprepared cleaning agent compositions, the following adhesive dissolutiontest was conducted. Specifically, the adhesive composition obtained inPreparation Example 2 was applied onto a 12-inch silicon wafer by meansof a spin coater and cured at 120° C. for 1.5 minutes and 200° C. for 10minutes. Subsequently, the cured adhesive composition was scraped off byuse of a cutter blade from the 12-inch wafer. A portion (1 g) of thecured adhesive composition was transferred to and weighed in a 9-mLscrew tube, and then the cleaning agent composition (2 g) was added tothe tube. The dissolution state of the cured product was observed at 23°C. When the cured product was substantially dissolved within 12 to 24hours, the state was rated as “Good.” When the cured product wassubstantially not dissolved over a long period of time, the state wasrated as “Bad.” Table 1 shows the results.

TABLE 1 Etching rate [μm/min] Dissolution test Ex. 1 8.2 Good Ex. 2 6.4Good Comp. Ex. 1 5.1 Bad Comp. Ex. 2 7.7 Bad Comp. Ex. 3 6.6 Bad Comp.Ex. 4 7.7 Bad Comp. Ex. 5 7.6 Bad Comp. Ex. 7 2.3 Bad

As shown in Table 1, the cleaning agent compositions falling within thescope of the present invention were found to exhibit an excellentcleaning speed and favorable persistency in cleaning performance, ascompared with those of the cleaning agent compositions of ComparativeExamples.

[3-3] Evaluation of Corrosibility

A silicon wafer was immersed for 5 minutes in each of the cleaning agentcompositions obtained in Examples 1 and 2. In all cases, no corrosion ofthe silicon wafer was observed.

1-10. (canceled)
 11. A cleaning agent composition for use in removal ofa polysiloxane adhesive remaining on a substrate, the compositioncomprising a tetrahydrocarbylammonium fluoride and an organic solvent,wherein the organic solvent contains an aromatic compound represented byformula (1) and a lactam compound represented by formula (2):

(wherein s represents the number of substituents R¹⁰⁰s of the benzenering and is 2 or 3; s groups of R¹⁰⁰s each independently represent a C1to C6 alkyl group; the total number of carbon atoms in s groups of C1 toC6 alkyl groups is 3 or greater; R¹⁰¹ represents a C1 to C6 alkyl group;and R¹⁰² represents a C1 to C6 alkylene group).
 12. The cleaning agentcomposition according to claim 11, wherein the lactam compound includesat least one member selected from N-methyl-2-pyrrolidone andN-ethyl-2-pyrrolidone.
 13. The cleaning agent composition according toclaim 11, wherein the aromatic compound includes at least one memberselected from among 1,2,3-trimethylbenzene, 1,2,4-trimethylbenzene,1,2,5-trimethylbenzene, 1,3,5-trimethylbenzene, 4-ethyltoluene,4-n-propyltoluene, 4-isopropyltoluene, 4-n-butyltoluene,4-s-butyltoluene, 4-isobutyltoluene, and 4-t-butyltoluene.
 14. Thecleaning agent composition according to claim 11, wherein thetetrahydrocarbylammonium fluoride includes at least one member selectedfrom among tetramethylammonium fluoride, tetraethylammonium fluoride,tetrapropylammonium fluoride, and tetrabutylammonium fluoride.
 15. Thecleaning agent composition according to claim 11, wherein the ratio bymass of the aromatic compound to the lactam compound (aromaticcompound:lactam compound) is 30:70 to 80:20.
 16. The cleaning agentcomposition according to claim 11, wherein the lactam compound includesat least one member selected from N-methyl-2-pyrrolidone andN-ethyl-2-pyrrolidone; the aromatic compound includes at least onemember selected from among 1,2,3-trimethylbenzene,1,2,4-trimethylbenzene, 1,2,5-trimethylbenzene, 1,3,5-trimethylbenzene,4-ethyltoluene, 4-n-propyltoluene, 4-isopropyltoluene, 4-n-butyltoluene,4-s-butyltoluene, 4-isobutyltoluene, and 4-t-butyltoluene; and thetetrahydrocarbylammonium fluoride includes at least one member selectedfrom among tetramethylammonium fluoride, tetraethylammonium fluoride,tetrapropylammonium fluoride, and tetrabutylammonium fluoride.
 17. Thecleaning agent composition according to claim 16, wherein the ratio bymass of the aromatic compound to the lactam compound (aromaticcompound:lactam compound) is 30:70 to 80:20.
 18. The cleaning agentcomposition according to claim 11, wherein the polysiloxane adhesiveremaining on a substrate is an adhesive residue originating from anadhesive layer formed from an adhesive composition containing acomponent (A) which is cured through hydrosilylation.
 19. A cleaningmethod, comprising removing an adhesive residue remaining on a substrateby use of the cleaning agent composition as recited in claim
 11. 20. Amethod for producing a processed semiconductor substrate, the methodcomprising: producing a laminate including a semiconductor substrate, asupport substrate, and an adhesive layer formed from an adhesivecomposition; processing the semiconductor substrate of the producedlaminate; debonding the semiconductor substrate after processing; andremoving an adhesive residue remaining on the debonded semiconductorsubstrate with a cleaning agent composition, wherein the cleaning agentcomposition as recited in claim 11 is used as the cleaning agentcomposition.